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水土流失——一个世界性的问题水土流失是一个世界性的问题,它几乎遍及各个国家和地区。严重的水土流失不仅造成生态环境的恶化,农林牧生产的全面衰退,而且对人类的生产和生活带来的威胁愈来愈大,因而引起人们的极大关注。据有关资料报导,在干旱和半干旱地区,由于超载过牧,土壤侵蚀危害,生产力下降,最后将导致土地的完全沙漠化。据估计,受到这种威胁的耕地为世界耕地的1/3以上。由于土壤侵蚀引起的土壤肥力退化,据联合国环境署估计,全世界每年损失可利用的土地为500—700万公顷,到本世纪末可能上升到1,000万公顷;其中占世界粮食生产52%的包括我国在内的
Soil and Water Loss - A Global Problem Soil and water loss is a worldwide problem that spreads to almost every country and region. Serious soil erosion has not only caused the deterioration of the ecological environment, the overall recession of agriculture, forestry and animal husbandry, but also brought more and more threats to the production and livelihood of human beings. Therefore, people have drawn great attention. According to relevant information, in the arid and semi-arid areas, due to over-grazing, soil erosion damage and productivity decline, it will eventually lead to the complete desertification of the land. It is estimated that arable land threatened by this threat is more than one-third of the world’s arable land. Due to degradation of soil fertility caused by soil erosion, the United Nations Environment Program estimates that the total annual loss of available land in the world is between 5 and 7 million hectares and may rise to 10 million hectares by the end of this century; 52% of the world’s grain production, including our country Including